Two groups of theoretical physicists delve into wormholes

One Wormhole Or Einstein-Rosen Bridge (By the two physicists who described it), it is a “tunnel” connecting distant points in time and space. They are actually the mathematical solutions of the field equations of Einstein’s general relativity.

According to the principles of physics, through these “shortcuts”, people can always reach other remote places in the universe at a speed lower than the speed of light, and they can also reach the future instead of the past.

At present, these space-time tunnels are only theoretical and have not yet been discovered, but physicists have not stopped proposing ways to pass gravity without clogging their “throat”. The last two proposals came from Europe and the United States.

One of the studies was published by a physicist Juan Martin Maldacena The School of Advanced Studies in the magazine and Alexey Milekhin of neighboring Princeton University (USA) in the magazine Physical Examination D. These authors use universe models with more than four dimensions to explain how humans cross one of these Einstein-Rosen bridges.

For its part, appearing in Medical letter, The teacher signs on it Jose Luis Blazquez Salcedo Researchers from the Complutense University of Madrid collaborated with Christian Knoll from the University of Oldenburg (Germany) and Eugen Radu from the University of Aveiro (Portugal). All three believe that they have found a novel way to traverse wormholes without having to rely on foreign matter as before.

The illustration of the wormhole in the curved space-time is a “tunnel” through which you can reach another place in the universe or a certain moment in the future. / ESO /L.Calzada

In principle, these two studies are consistent with the principles of known physics, although there are some differences between the two groups in this regard. In order to better understand the details, it is convenient to make contextual associations and remember that the existence of wormholes that can be entered and exited requires mass energy distribution that violates several energy conditions.

Foreign body in the hole

As a solution, some models have been proposed, which show that there are various types of Exotic. This will provide the necessary force to counteract the gravitational attraction in the hole, thereby keeping it open.

The problem is that this foreign matter is not within the scope of the accepted standard model of particle physics.An example of this strange thing is the so-called Ghost scalar field, It has negative kinetic energy and has never been observed in nature.

This Scalar field This type of sensor commonly used in traversable wormhole models is composed of Boson, Is one of the two basic elementary particles in nature (such as W, Z or Higgs).

Bosons are mathematically simple, so they are usually the first choice in theoretical analysis.its Spin, For example, it is an integer (0, 1, 2…). However, the only basic scalar field observed in nature is the Higgs boson, which does not support wormhole geometry.

But, on the other hand, these mysterious objects can also be explained by another type of particle in nature: Fermions, For example, the group to which electrons and quarks belong. Its spin can be half integer: 1/2, 3/2…

In this case, Maldacena and his colleagues from Princeton proposed a solution to wormholes based on a theory that speculates on extra dimensions. These wormholes may be considered to be beyond the standard model. Material possibility: Randall Sandrum.

In superstring theory and bran cosmology, this model was proposed by Lisa Randall (explained at the Autonomous University of Madrid a few years ago) and Raman Sundrum, describing the Five dimensions, Almost all elementary particles are fixed in the “membrane”.

under these circumstances, Extra dimension It is responsible for generating negative energy, can keep the throat of the wormhole open, and has a very slender geometric shape.

Maldacena emphasized to SINC: “The material used in the strange solution we use has not been discovered yet, and it is likely that it does not exist in our universe.” Respect the basic principles of known physicsJust like relativity quantum mechanics, it is different from the previous wormhole proposal.

Move between galaxies in less than a second

According to his model, considering time from the perspective of a traveler, a person can travel between the Milky Way through one of these tunnels in less than a second, because it would take thousands of years for external observers. time.

J. Maldacena and A. Milekhin studied the geometry of wormholes. /D version

Ordinary things to be solved

The European team took a “semi-classical” approach and took a step forward and proposed a way to travel through time and space. They not only considered respect for physical principles, but also used ordinary matter: quantum wave function.

“In our research, for the first time, we established a traversable wormhole in the Einstein-Dirac-Maxwell theory, that is, without introducing foreign matter,” Blazquez pointed out to SINC, insisting that : “We think of the standard model of particle physics, and we use Einstein’s theory of gravity.”

use Einstein-Maxwell-Dirac Theory It involves three aspects it contains: Einstein’s general theory of relativity for gravity, Maxwell’s electromagnetic field for the interaction of matter, and Dirac’s general theory of relativity for fermions.

The Spanish physicist emphasized: “The Dirac field naturally violates the energy condition, so fermions can provide additional interactions to balance gravity and keep the wormhole open.”

The black hole solution proposed by the JLBlázquez Salcedo team has an enlarged “throat” area. /Physics Pastor Lett.

Braques admitted: “Due to the quantum nature of fermions, we assume that the existing wormholes will be microscopic”, although his discovery opened up new ways for other gravitational models and theoretical research on other gravitational models. Or include more quantum effects.

Debate among theoretical physicists

Although the European team pointed out that their black hole proposal uses ordinary matter and conforms to known physics, Maldacena questioned this: “The heterogeneous matter used in your article does not conform to physical principles, and therefore is incompatible with other The substances are similar. The previous suggestion. In particular, they use the 1/2 spin field of boric acid instead of iron ions.”

Blazquez didn’t completely agree: “In our work, Dirac Field Be restricted to a specific state, which is called Singlet. This field has spin 1/2 and is Fermi ion. We normalize the wave function and obey the Poly exclusion principle, so it is consistent with the physics principle.

In any case, his acceptance of criticism is also reflected in his own criticism paper Message from the European team: “Although our model does not include foreign substances, it does not Quantum effect, They are undoubtedly very important. These may change the nature of wormholes and even prevent the existence of wormholes, so more research is needed. ”

The debate between the two groups of theoretical physicists and their research continues, and this usually continues to develop in science. In any case, we can still find a wormhole through which we can pass, and it still seems very far away: “I think, at least among the worms we are discussing here, we will never find them.” Know if there will be other possibilities in the future .